1. Field of the Invention
This invention relates to high-strength magnesium-based alloys obtained by the rapid solidification method or quench solidifying method.
2. Description of the Prior Art
The magnesium-based alloys heretofore known to the art include those of the compositions of Mg-Al, Mg-Al-Zn, Mg-Th-Zr, Mg-Th-Zn-Zr, Mg-Zn-Zr, and Mg-Zn-Zr-RE (rate earth element). Depending on their material characteristics, these magnesium-based alloys have been finding extensive utility as light-weight structural materials for aircraft and vehicles, as materials for storage batteries, and as sacrifice electrodes, for example. The conventional magnesium-based alloys of varying types cited above, however, are generally deficient in hardness and strength.
As materials obtainable by the rapid solidification method, magnesium-based alloys of varying compositions have been developed. For example, Japanese Patent Application laid open to public inspection, KOKAI (Early Publication) No. 3-87339 (87,339/1991) discloses a magnesium-based alloy of Mg-M-X [wherein M stands for Al, Si, Ca, Cu, Ni, Sn, or Zn and X for Y, La, Ce, Sm, Nd, or Mm (misch metal)] and Japanese Patent Application, KOKAI No. 3-10041 (10,041/1991) discloses magnesium-based alloys of Mg-X, Mg-X-M, Mg-X-Ln, and Mg-X-M-Ln (wherein X stands for Cu, Ni, Sn, or Zn, M for Al, Si, or Ca, and Ln for Y, La, Ce, Nd, Sm, or Mm). These magnesium-based alloys, however, are amorphous alloys containing at least 50% by volume of an amorphous phase.
As respects crystalline magnesium-based alloys, Japanese Patent application, KOKAI No. 3-47941 (47,941/1991) discloses magnesium-based alloys of Mg-X, Mg-X-M, Mg-X-Ln, and Mg-X-M-Ln (wherein X stands for Cu, Ni, Sn, or Zn, M for Al, Si, or Ca, and Ln for Y, La, Ce, Nd, Sm, or Mm). Though the magnesium-based alloys reported in said Japanese Patent application, KOKAI No. 3-47941 are excellent in hardness and tensile strength, they are imperfect in terms of thermal stability and specific strength and have room for improvement.